photo_combine_3_colors

%matplotlib inline
from skimage.io import imread, imshow, imsave
from skimage import img_as_float
import numpy as np
import logging

logger = logging.getLogger()
logger.setLevel(logging.DEBUG)

def read_and_split(image):
    img = imread(image)
    logger.debug("size of photo:", img.shape)
    height_div_3 = img.shape[0] // 3
    b = img[ : height_div_3, : ]
    g = img[height_div_3 : 2 * height_div_3, : ]
    r = img[2 * height_div_3 : 3 * height_div_3, : ]
    logger.debug(b.shape, g.shape, r.shape)
    b, g, r = list(map(img_as_float, (b, g, r, )))
    return b, g, r

def clip_border(b, g, r):
    height, width = b.shape
    centre_part = lambda x: x[height//20 : -height//20 , width//20 : -width//20]
    b = centre_part(b)
    g = centre_part(g)
    r = centre_part(r)
    return b, g, r

def find_shift(canal_1, canal_2, axis, max_shift = 15):
    min_corelation = 0
    right_shift = 0
    for shift in range(-max_shift, max_shift + 1):
        canal_2_shift = np.roll(canal_2, shift, axis)
        current_corelation = (canal_1 * canal_2_shift).sum()
        if current_corelation > min_corelation:
            min_corelation = current_corelation
            right_shift = shift
    return right_shift

def combine_image(r, g, b, gr_x, gr_y, gb_x, gb_y):
    r_sh = np.roll(r, gr_x, axis = 0)
    r_sh = np.roll(r_sh, gr_y, axis = 1)
    b_sh = np.roll(b, gb_x, axis = 0)
    b_sh = np.roll(b_sh, gb_y, axis = 1)
    combined_img =  np.stack((r_sh, g, b_sh), 2)
    return combined_img

def result_img(image):
    b, g, r = read_and_split(image)
    b, g, r = clip_border(b, g, r)
    gr_x = find_shift(g, r, 0)
    gr_y = find_shift(g, r, 1)
    gb_x = find_shift(g, b, 0)
    gb_y = find_shift(g, b, 1)
    logger.debug(gr_x, gr_y)
    logger.debug(gb_x, gb_y)
    result_img = combine_image(r, g, b, gr_x, gr_y, gb_x, gb_y)
    return result_img

def align(image, green_point_coord):
    row_g, col_g = green_point_coord
    b, g, r = read_and_split(image)
    h_dif = b.shape[0]
    b, g, r = clip_border(b, g, r)

    gb_x = find_shift(g, b, 0)
    gb_y = find_shift(g, b, 1)
    gr_x = find_shift(g, r, 0)
    gr_y = find_shift(g, r, 1)

    print(gr_x, gr_y)
    print(gb_x, gb_y

    row_b = row_g - gb_x - h_dif
    col_b = col_g - gb_y
    row_r = row_g - gr_x + h_dif
    col_r = col_g - gr_y
    return row_b, col_b, row_r, col_r

align("https://stepik.org/media/attachments/lesson/58182/00.png", (508, 237))